The present invention relates to controller and control method for an engine for controlling an idling reduction (an idling stop) system.
There are cases where the idling reduction system that stops the engine when a predetermined condition is established at a vehicle stopping time is loaded on recent vehicles in order to improve fuel efficiency. As one example of the condition that stops the engine, a condition that a transmission is shifted into neutral, a parking brake is actuated, and a service brake is released is applied as described in Japanese Patent Application Laid-Open Publication No. 2013-104385 (Patent Document 1). This condition is the one that a parking state that the vehicle stops for a long period of time is taken into account and is applied, in particular, to commercial vehicles in many cases.
Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2013-104385
However, the state that enables the engine to stop covers not only a parking state but also a halted state where the vehicle is temporarily stopped with a traffic signal and so forth. Although there are cases where the idling reduction system that stops the engine in the halted state is loaded on passenger cars and so forth, in heavy-duty and medium trucks, it is not expected to stop the engine in the halted state. Incidentally, in the passenger cars and so forth, it is not expected to stop the engine in the parking, state.
Accordingly, it is desirable to provide controller and control method for an engine that have promoted further improvement of the fuel efficiency by stopping the engine in the halted state and the parking state.
The controller for an engine has a sensor that detects an actuating state of a service brake, a sensor that detects the actuating state of a parking, brake, a sensor that detects a gear shift state of a transmission, and a control unit that controls the engine at a vehicle stopping, time, according to output signals from the sensors. Then, the control unit stops the engine when a first condition that the service brake is released, the parking brake is actuated, and the transmission is shifted into neutral has been established, or a second condition that the service brake is actuated and the transmission is shifted to an ahead stage has been established.
According to an aspect of the present invention, since the condition that stops the engine is increased, further improvement of the fuel efficiency can be promoted.